I don't think there is enough information to make reasonable reserve calculations but I'll try. Some people make prediction regarding LCK but the company provided more information (potential yearly sales and potential reserve life).
If RLE manages to produce average 20TJ per day (the number for Stage 1 development). It gives 7300TJ per year or 7.3 PJ. Assuming it can produce for 20 years with the given reserve, then 146PJ Reserve
RLE Price at posting:
9.7¢ Sentiment: Hold Disclosure: Held